I’m afraid Mr. Harding_________see you now. He’s busy.
| A．can’t | B．mustn’t | C．shouldn’t | D．needn’t |
It hasn’t been announced ______ the plane is to take off.
| A．where | B．when | C．how | D．why |
Students ______ to do some voluntary work every year.
| A．were encouraged | B．are encouraged |
| C．encourage | D．encouraged |
You can smoke here ______ you leave a window open to let the smoke out.
| A．even though | B．so that | C．as long as | D．in case |
It is usually cheaper to have the goods ______ by sea than by air.
| A．sent | B．to send | C．sending | D．being sent |
The pianist ______ a love for music when he was a little boy.
| A．develops | B．has developed |
| C．developed | D．had developed |